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DESTINATION MOON: A History of the
Lunar Orbiter Program
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- CHAPTER VII: BUILDING THE
SPACECRAFT: PROBLEMS AND RESOLUTIONS
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- Problem Areas: Last Quarter
1964 to First Half 1965
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- [163] Several problem
areas had developed by late 1964 which threatened the original
schedules of the program. Some of these have already been
mentioned. Two more are noteworthy, however. At the Lunar Orbiter
Preliminary Design Review held at Boeing on October 27 and 28,
1964, the status of the micrometeoroid and radiation experiments
had somewhat alarmed Israel Taback, the Langley Lunar Orbiter
Spacecraft Manager, and Martin J. Swetnick, the Lunar Orbiter
Program Scientist from NASA Headquarters. They learned that the
instrumentation which Boeing proposed to procure for the two
experiments by letting bids to Space [164] Technology
Laboratories or Texas Instruments, Inc., did not meet the actual
specifications in the experiments document. Indeed Taback and
Swetnick felt that even the specifications document which Boeing
had drawn up did not demonstrate an understanding of the
experiments which the Lunar Orbiter Project Office desired to have
on board the spacecraft.
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- Swetnick called a special meeting with
Boeing representatives on October 29 for a detailed discussion of
Boeing's approach to the experiments. He and Taback made clear to
the contractor that Boeing's specifications document for the
radiation experiment was very confusing because "it did not in any
way provide the bidders with a description of the requirements for
the radiation data, a statement of objectives, and a description
of what should be done."34 Boeing's lack of knowledge about the radiation
experiment surprised the two NASA officials, who urged Boeing to
work out a more realistic approach to fabrication and testing of
the experiments instrumentation as Dr. Foelsche had designed
it.
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- The October 29 meeting revealed the
existence of poor communications between Langley and Boeing in the
area of experiments. Boeing did not lack .the ability to carry out
[165]
the work required or to obtain competent support for the work.
Instead Boeing personnel responsible for the experiments had not
understood precisely what Langley desired them to do. Boeing
management officials realized that they needed to modify the
specifications document to give their bidders a much clearer idea
of the nature and objectives of the two experiments. They assured
Taback that they would send the modified document to Langley for
review and approval before submitting it to the bidders.
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- The problem with the micrometeoroid
experiment was different. Boeing had made certain design changes
on it without notifying the principal investigator, Charles A.
Gurtler at Langley. Taback and Swetnick were disturbed that Boeing
had decided to locate the micrometeoroid pressure cells on the
periphery of the tank deck (middle deck) outside the thermal
blanket, necessitating reduction of the number of cells from 20 to
15. Worse yet, the leads from the cells to the respective
electronics would have to pass through the thermal blanket. Taback
made it clear that Langley would have to examine this alteration
very carefully before making a decision on. the experiment's final
design.35
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- [166] Swetnick told
the Boeing people that Gurtler did not believe that the experiment
could be useful with fewer than 20 cells and any change in their
location would require substantial redesign. Again the fact that
Langley. officials were unaware of Boeing's thinking on the
micrometeoroid experiment showed a surprising lack of
communication, steps were taken to strengthen ties between the
Langley LOPO people and their Boeing counterparts.
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- Another problem of note was the status of
the Lockheed Agena D launch vehicle, its adapter, and the
spacecraft shroud. The Lewis Research Center near Cleveland, Ohio,
had the responsibility for these pieces of hardware. Early in 1964
Lewis had insisted that Lockheed handle the entire integration of
the booster-adapter-shroud hardware for Lunar Orbiter. Langley had
proposed to have Boeing provide the adapter and the shroud. This
arrangement had not been acceptable to Lewis. Dr. Abe Silverstein,
the center's director, had personally guaranteed that the adapter
and the shroud would be delivered to the Boeing Company at the
time stipulated in the contract.36 By late 1964 Lewis was confronted with the
predicament that Lockheed, as sole vendor of the hardware, was not
going to [167] meet the target dates for delivery. Moreover, to
meet its schedule might cause it to overrun the original contract
price by as much as 100%. Realizing this, Lewis desired to open
the field to competitive bidding for the hardware, but it had to
wait for a Headquarters review of the situation before making such
a move.37
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- Scherer's office at NASA Headquarters was
disturbed by the unforeseen turn of events at Lewis. Lockheed had
failed to provide Boeing with an adapter master gauge on December
1. 1964, as it had promised; and Boeing still did not have one by
January 5. Worse yet Lewis had not finalized the adapter design by
the beginning of 1965, and this would impinge upon program
schedules unless NASA Headquarters quickly altered the situation.
Boeing, meanwhile, had sent Lockheed a model of the spacecraft on
January 4 for separation tests with the Agena, but it remained
uncrated pending a decision by NASA to open the field for
competitive bids for the adapter and the
shroud.38
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- By February 8, 1965, Lewis had opened
bidding for the spacecraft adapter, the Atlas SLV-3 and the Agena
D launch vehicles. Headquarters gave Lewis permission to open
[168]
bidding on the shrouds and the bidding began on February
5.39 On March 8 Lewis awarded Lockheed the adapter
hardware contract, and in the interim Lewis delivered the Adapter
Master Gauge to Boeing.40 Boeing, intent upon avoiding any delays or
compatibility problems, bid for the spacecraft shroud and was
awarded the contract by Lewis on April 1. Boeing would build two
ground-test shrouds and five flight shrouds for its Lunar
Orbiter.41 On April 26 Lewis sent Boeing a shroud from the
Mariner D spacecraft to be used as a "stand-in" for tests with
component sets A and C.42 These progressive actions by Lewis corrected a
situation which could have caused substantial schedule slippage,
possibly affecting the incentives in the Boeing contract.
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- From February 24 through 26, Langley held
the Third Quarterly Review. During the review three meetings
convened to examine the status of the spacecraft, the results of
the Critical Design Review and the interrelations of the
[169]
program's various systems: spacecraft, launch vehicle, and
tracking and data acquisition.
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- Boeing reported that the late availability
of hardware from Eastman Kodak and RCA had necessitated a schedule
adjustment moving prototype systems tests back eight weeks.
Beginning in November 1964 Eastman Kodak had to rearrange its
schedules with Boeing because its hardware deliveries would not
come in time to undergo testing with the spacecraft component
sets. Instead Boeing had to use a photographic subsystem simulator
during the design verification tests.43
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- By late January 1965 the photo subsystem
was still experiencing delays. Eastman Kodak had problems in
procuring high-reliability parts and in a power change for the
subsystem. The 610 mm lens was also a problem, because of
difficulties in attaining the proper resolution; Kodak, however,
succeeded in eliminating the error in the lens formula and
proceeded with fabrication.44 The delays did not change the first launch date
because the program used the parallel testing mode. However,
Langley deleted the Flight Acceptance Test on Spacecraft 1 and
established [170] testing restraints to fit the schedule changes
because of the delays at Eastman Kodak.45
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- Boeing also reported to the members of the
Third Quarterly Review that all designing was essentially
completed and a substantial amount of structural and thermal
testing of components had been conducted. No serious failures or
deficiencies in components had been uncovered during testing.
Nevertheless a few hardware items did have problems: 1) the design
and operation of the camera thermal door; 2) telemetry data
handling during testing; 3) the photographic recording equipment
at DSIF Site 71 (located at Cape Kennedy), and 4) several
potential trouble areas in the spacecraft's film processing
system. Work on these items did not threaten schedules or hinder
the progress of other subsystems in any substantial ways largely
because of the loose integration of all subsystems in the
spacecraft system design.
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- Boeing officials also noted at the review
that the situation at Lewis was improving and being monitored by
NASA Headquarters. Finally, the men present at the Third Quarterly
Review decided to have Boeing conduct "qualification tests on S/C
1, one mission simulation test on S/C 2, and [171] phase one of the
Goldstone Test on S/C 3 ... prior to the start of FAT on the first
flight spacecraft."46
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- By early March Langley had altered the
testing program, removing several conservative features in the
initial phase of testing to allow for further schedule
compression. At the same time restraints were established which
required that 1) the qualification and reliability tests of each
component for a flight spacecraft had to be completed before the
Flight Acceptance Test on the component could begin and that 2) no
FAT of an entire flight spacecraft would commence before the
completion of qualification tests on Spacecraft 1, of one mission
simulation test on Spacecraft 2, and of the first phase of the
Goldstone Test on Spacecraft 3.47 These steps left little room for any major testing
failures without causing serious schedule slippages. This was a
risky, but one which was calculated, relying on testing procedures
at the component level to catch and correct any design or
fabrication anomalies before they could reach the subsystem
integration level undetected and have a serious impact on the
program's timetable.
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- [172] One example of
the early detection of such an anomaly had come to light during
the February 17 Photographic Subsystem Critical Design Review.
Leon Kosofsky, Headquarters Program Engineer, reported to Israel
Taback., Langley LOPO Spacecraft Manager, in a memorandum dated
March 4 that "the film processor cannot be stopped indefinitely
without the risk of losing the mission due to the sticking of the
Bimat web to the exposed film."48
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- This condition meant that either the
processor or the mission design would have to be altered. At least
some of the film would have to be wasted to keep the whole film
and the Bimat processing web (film) advancing at a rate sufficient
to preclude any sticking.
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- The Lunar Orbiter Program Office had to
know the time the Kodak SO-243 film and the Bimat could safely
remain in contact during a non-photographic period. Kosofsky
pointed out that, as matters stood, if this time were 3.5 hours or
less, then a typical mission such as that envisioned in Bellcomm
report TR-65-211-1 (January 25, 1965) would be
impossible.49 If the safe time was between 3.5 [173] and 6.33 hours,
waste exposures would be required on every non-photographic orbit
of the Moon, because of the forty-minute processing period which
could be subtracted from the time requirement of a photographic
and a non-photographic orbit combined. Finally, a safe time of 7.5
hours meant that wasted exposures would be required only on
alternate orbits during non-photographic periods, while a 10.5
hours safe time would allow two successive orbits during such
periods without having to waste film. This problem presented
sufficient potential impact upon Lunar Orbiter's mission
capabilities to require immediate study of ways to reduce or
eliminate film wastage regardless of the final processor safe
time.50
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- The amount of time wasted in the readout
process by blank pictures presented one of the worst aspects of
the film advance problem. As of March 4, 1965,the design of the
photographic subsystem precluded any rapid operation of the rewind
drive. Unless changed, this problem would severely affect the
critical readout process. Kosofsky instructed G. Calvin Broome,
Chief of the Photo Subsystem Section of the Langley LOPO, to
explore ways of overcoming the necessity to waste film and prolong
the readout [174] process.51
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- Except for several minor problems the
Lunar Orbiter design phase was completed by April 13, 1965; over
80% of the procurement had been started and over 60% of the first
sets of components had been delivered to the contractor.
Development tests had begun and mission planning for Orbiter was
just commencing. The Kent Testing Facility at Boeing in Seattle
also neared completion. Boeing would use it for the spacecraft's
mission simulation tests. It consisted of a major chamber with a
working section 12 meters high by 9 meters in diameter, capable of
having its internal pressure pumped down at twice the rate of the
planned Lunar Orbiter ascent profile for the mission
simulation-tests. Other smaller chambers were also part of this
listing facility.52
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- By the middle of 1965 the Lunar Orbiter
Program was well into its major development phase. The Program
Office and the Project Office at Langley had maintained an
equilibrium among the many different needs which had to be
fulfilled, and among working groups at Langley, Boeing,
[175]
the Jet Propulsion Laboratory, Lewis, and the major
subcontractors. Langley maintained tight control of its funds and
the rate of funding required by Boeing as the program moved into
the mission planning phase.
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